I would definitely recommend Captain Dave's! They sell 49 tickets for that boat (Manute'a) and I would guess there were about 30 people onboard. Even if it were full, it wouldn't be quite as cool obviously, but I don't think it would be crazy. They say on the website that they sell fewer tickets than the boats are rated for and I believe them. You can stalk their
reservations page; if you hover over the time each day, it will tell you how many seats are available and which boat is going out. I have a feeling it's relatively uncrowded when it's not peak whale season. Unfortunately, I didn't grab many shots of the actual boat, but there's the front where we spent pretty much all of our time, a pretty big "inside", plus more area in the back with benches at the very back and more standing area along the sides.
The front is three of those net thingys wide with standing space all along the outside.
You can see the entrance to the pod here right behind the blue nets. There's one on either side. When the pods aren't open, the hatch is closed so there's even more standing space up front.
The line for the underwater pods really wasn't bad at all. I actually went down three times: once with J.J. right when they opened them, and once with each of the kids towards the end because there was no line. Unless a whale surfaced off in the distance, I don't think there's much that you'd miss being in the pod. The dolphins really liked to swim alongside the boat right next to and in front of the hulls where the pods are. The pod is really the place to be, IMO. Most of the time I was up on deck, I was watching the dolphins that were swimming right next to where the pods are. You wouldn't miss anything while you were standing in line for the pod. The boat was comfortably roomy for the number of people on board, but there's still not a ton of extra space. If you're waiting for the pod, you're still basically in that prime viewing area up front.
You also get what I bet is pretty reliable viewing of California sea lions. They like to hang out on the buoys: